Frictional connections are frequently used to transmit transverse forces or torques in all fields of mechanical engineering. The magnitude of the force which can be transmitted in each case depends not only on the structural circumstances but first and foremost on the coefficient of static friction of the component surfaces to be connected to one another. Steel/steel pairings typically have coefficients of static friction of 0.15, which due to the increasingly demanding requirements to be met by machine components frequently is not sufficient for a secure frictional connection.
Physical locking or micro-physical locking enables the force which can be transmitted to be increased at a constant contact pressure. This principle has been known for a long time, for example by introduction of sand into the gap of a joint. However, this type of introduction of particles is very undefined and in the case of relatively coarse particles which preferentially remain lodged in the gap, there is a considerable increase in the risk of initiation of cracks in the base material.
Likewise, screw connections are used in all fields of machine, plant and vehicle construction in order to achieve frictional connections. Particularly in the case of dynamic stressing of the screw connections, many conventional screw connections do not ensure sufficient security against spontaneous release of the screw connections. Efforts are therefore made to provide measures for securing screw connections in order to prevent spontaneous release of the screw connections in the case of high and in particular dynamic stresses.